在执行一些与焦点相关的事情时获取nullreferenceexception后，我的应用程序崩溃了 [英] My application gets crashed after getting nullreferenceexception while doing some focus related things

问题描述

I am working on an application where we can open child modules using multiple tab display. But when someone switches between the tabs so frequently or clicks on a tab more than once then sometimes I got fatal nullreference exception which further crash my whole application. I have applied complete exception handling but this exception is not getting caught anywhere. I think this might be some windows related exceptions which are happening on the kernel. I am posting the call stack also and to get the info on the exception I used profiling tool.

System.NullReferenceException occurred Message: Exception thrown: 'System.NullReferenceException' in System.Windows.Forms.dll Additional information: Object reference not set to an instance of an object.

This call stack is above of the below call stack - this I got from the profiling tool.

> class =System.Windows.Forms.UnsafeNativeMethodsmethod =WaitMessage（）

class =System.Windows.Forms.Application + ComponentManagermethod =System.Windows.Forms。 UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop（System.IntPtr，INT，INT）

类= System.Windows.Forms.Application + ThreadContext 方法= RunMessageLoopInner（INT，System.Windows.Forms.ApplicationContext ）

class =System.Windows.Forms.Application + ThreadContextmethod =RunMessageLoop（int，System.Windows.Forms.ApplicationContext）

class = System.Windows.Forms.Applicationmethod =RunDialog（System.Windows.Forms.Form）

class =System.Windows.Forms.Formmethod =ShowDialog（System.Windows。 Forms.IWin32Window）

class =System.Windows.Forms.Formmethod =ShowDialog（）

class =OuterNamespace.Portal.Utilities.Forms。 MessageBoxEx method =Show（System.String，System.String，System.Windows.Forms.MessageBoxButtons，System.Windows.Forms.MessageBoxIcon）

class =OuterNamespace.Portal.Utilities.Forms.MessageBoxEx method =Show（System.String，System.Windows.Forms.MessageBoxButtons，System.Windows.Forms.MessageBoxIcon）

class =OuterNamespace.Portal.Components.ExceptionHandlermethod =Handle （System.Exception，System.String，OuterNamespace.Portal.Constants.Logging.LogType）

class =OuterNamespace.Portal.Components.ExceptionHandlermethod =HandleException（System.Exception，boolean， OuterNamespace.Interfaces.RuntimeInformation.IRuntimeInformationManager）

class =OuterNamespace.Exception.Manager.ExceptionManagermethod =CallUnhandledExceptionHandler（System.Exception）

class =OuterNamespace .Exception.Manager.ExceptionManagermethod =HandleUnhandledException（System.Exception）

class =OuterNamespace.Application.ApplicationContextmethod =Application_ThreadException（Sys tem.Object，System.Threading.ThreadExceptionEventArgs）

class =System.Windows.Forms.Application + ThreadContextmethod =OnThreadException（System.Exception）

class =System.Windows.Forms.Controlmethod =WndProcException（System.Exception）

class =System.Windows.Forms.Control + ControlNativeWindowmethod =OnThreadException（System.Exception） ）

class =System.Windows.Forms.NativeWindowmethod =Callback（System.IntPtr，int，System.IntPtr，System.IntPtr）

class =System.Windows.Forms.UnsafeNativeMethodsmethod =SetFocus（System.Runtime.InteropServices.HandleRef）



---------- -------------------------------------------------- ------------

System.Windows.Forms.dll！System.Windows.Forms.ContainerControl.FocusActiveControlInternal（）Unknown

系统。 Windows.Forms.dll！System.Windows.Forms.ContainerControl.WmSetFocus（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windo ws.Forms.ContainerControl.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.UserControl.WmSetFocus（ref System.Windows。 Forms.Message m）未知

System.Windows.Forms.dll！System.Windows.Forms.UserControl.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.ControlNativeWindow.OnMessage（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System。 Windows.Forms.Control.ControlNativeWindow.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr） hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam）Unknown

[本机到托管转换]

[管理到本机转换]

System.Windows.Forms.dll！System.Windows.Forms.ContainerControl.FocusActiveControlInternal（）Unknown

System.Windows。 Forms.dll！System.Windows.Forms.ContainerControl.WmSetFocus（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Form.WndProc （ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.ControlNativeWindow.OnMessage（ref System.Windows.Forms.Message m） Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.ControlNativeWindow.WndProc（ref System.Windows.Forms.Message m）Unknown

系统。 Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam）Unknown

System.Windows.Forms.dll ！System.Windows.Forms.NativeWindow.DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.WndProc（ref System .Windows.Forms.Message m）未知

Module.dll！MyNamespace.Wrappers.WindowWrapper.WndProc（ref System.Windows.Fo rms.Message m）未知

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam） Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows。 Forms.dll！System.Windows.Forms.NativeWindow.WndProc（ref System.Windows.Forms.Message m）Unknown

Module.dll！MyNamespace.Wrappers.WindowWrapper.WndProc（ref System.Windows。 Forms.Message m）未知

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam） Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows。 Forms.dll！System.Windows.Forms.NativeWindow.WndProc（ref System.Windows.Forms.Message m）Unknown

Module.dll！MyNamespace.Wrap pers.WindowWrapper.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg ，System.IntPtr wparam，System.IntPtr lparam）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.WndProc（ref System.Windows.Forms.Message m）Unknown

Module.dll！MyNamespace。 Wrappers.WindowWrapper.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg ，System.IntPtr wparam，System.IntPtr lparam）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.WndProc（ref System.Windows.Forms.Message m） Unknown

Module.dll！MyNamespace.Wrappers.WindowWrapper.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System。 Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow .DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.WndProc（ref System.Windows.Forms.Message m） Unknown

Module.dll！MyNamespace.Wrappers.WindowWrapper.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System。 Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow .DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWin dow.WndProc（ref System.Windows.Forms.Message m）Unknown

Module.dll！MyNamespace.Wrappers.WindowWrapper.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam）Unknown

System .Windows.Forms.dll！System.Windows.Forms.NativeWindow.DefWndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms。 NativeWindow.WndProc（ref System.Windows.Forms.Message m）Unknown

Module.dll！MyNamespace.Wrappers.WindowWrapper.WndProc（ref System.Windows.Forms.Message m）Unknown

System.Windows.Forms.dll！System.Windows.Forms.NativeWindow.Callback（System.IntPtr hWnd，int msg，System.IntPtr wparam，System.IntPtr lparam）Unknown

[本地到托管转换]

[管理到本机转换]

Module.dll！MyNamespace.FocusController.FixMo useDoubleClickError.AnonymousMethod__68_0（）未知

[本机到托管转换]

[管理到本机转换]

mscorlib.dll！System.Delegate。 DynamicInvokeImpl（object [] args）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.InvokeMarshaledCallbackDo（System.Windows.Forms.Control.ThreadMethodEntry tme）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.InvokeMarshaledCallbackHelper（object obj）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control。 InvokeMarshaledCallback（System.Windows.Forms.Control.ThreadMethodEntry tme）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.InvokeMarshaledCallbacks（）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.MarshaledInvoke（System.Windows.Forms.Control调用者，System.Delegate方法，object [] args，bool同步）Unknown

系统.Windows.Forms.dll！System.Windows.Forms.Control的。 Invoke（System.Delegate方法，object [] args）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.Invoke（System.Delegate method）Unknown

Module.dll！MyNamespace.FocusController.FixMouseDoubleClickError（）未知

Module.dll！MyNamespace.FocusController.UpdateAsyncIff.AnonymousMethod__91_0（）未知

[本机到托管转换]

[管理到原生过渡]

mscorlib.dll！System.Delegate.DynamicInvokeImpl（object [] args）Unknown

System.Windows .Forms.dll！System.Windows.Forms.Control.InvokeMarshaledCallbackDo（System.Windows.Forms.Control.ThreadMethodEntry tme）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control .InvokeMarshaledCallbackHelper（obj对象）未知

mscorlib.dll中！System.Threading.ExecutionContext.RunInternal（System.Threading.ExecutionContext的ExecutionContext，System.Threading.ContextCallback回调，对象状态，布尔preserveSyncCtx）未知

mscorlib.dll！System.Threading.ExecutionContext.Run（System.Threading.ExecutionContext executionContext，System.Threading.ContextCallback callback，object state，bool preserveSyncCtx）Unknown

mscorlib。 dll！System.Threading.ExecutionContext.Run（System.Threading.ExecutionContext executionContext，System.Threading.ContextCallback callback，object state）Unknown

System.Windows.Forms.dll！System.Windows.Forms。 Control.InvokeMarshaledCallback（System.Windows.Forms.Control.ThreadMethodEntry tme）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.InvokeMarshaledCallbacks（）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.MarshaledInvoke（System.Windows.Forms.Control caller，System.Delegate method，object [] args，bool synchronous）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Control.Invoke（System.Delegate方法，object [] args）未知

System.Windows.Forms.dll！System.Windows。形成s.Control.Invoke（System.Delegate方法）未知

Module.dll！MyNamespace.FocusController.FixMouseDoubleClickError（）未知

Module.dll！MyNamespace.FocusController.HandleCpmModalForegroundWindow（ System.IntPtr appForegroundWinHdl）未知

的Module.dll！MyNamespace.FocusController.HandleForegroundWindowChange（System.IntPtr foregroundDetectedHdl）未知

的Module.dll！MyNamespace.FocusController.ForegroundWindowChangeDetectorOnForegroundWindowChanged（对象发件人，MyNamespace.Detectors.ForegroundEventArgs foregroundEventArgs）未知

的Module.dll！MyNamespace.Detectors.ForegroundWindowChangeDetector.OnForegroundWindowChanged（MyNamespace.Detectors.ForegroundEventArgs E）未知

的Module.dll！myNameSpace对象.Detectors.ForegroundWindowChangeDetector.ForegroundCallback（System.IntPtr eventHook，UINT EVENTTYPE，System.IntPtr HWND，INT idObject，INT idChild，UINT dwEventThread，UINT dwmsEventTime）未知

[原产于管理d转换]

[管理到本机转换]

System.Windows.Forms.dll！System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods .IMsoComponentManager.FPushMessageLoop（System.IntPtr dwComponentID，诠释原因，诠释pvLoopData）未知

System.Windows.Forms.dll的！System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner（INT原因，系统。 Windows.Forms.ApplicationContext context）Unknown

System.Windows.Forms.dll！System.Windows.Forms.Application.ThreadContext.RunMessageLoop（int reason，System.Windows.Forms.ApplicationContext context）Unknown

Portal.Desktop.exe！OuterNamespace.Portal.Desktop.Program.Main（）未知



我的尝试：



我无法解决问题，因此无法找到解决方法或任何修复方法。

>class="System.Windows.Forms.UnsafeNativeMethods" method="WaitMessage()"
class="System.Windows.Forms.Application+ComponentManager" method="System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(System.IntPtr,int,int)"
class="System.Windows.Forms.Application+ThreadContext" method="RunMessageLoopInner(int,System.Windows.Forms.ApplicationContext)"
class="System.Windows.Forms.Application+ThreadContext" method="RunMessageLoop(int,System.Windows.Forms.ApplicationContext)"
class="System.Windows.Forms.Application" method="RunDialog(System.Windows.Forms.Form)"
class="System.Windows.Forms.Form" method="ShowDialog(System.Windows.Forms.IWin32Window)"
class="System.Windows.Forms.Form" method="ShowDialog()"
class="OuterNamespace.Portal.Utilities.Forms.MessageBoxEx" method="Show(System.String,System.String,System.Windows.Forms.MessageBoxButtons,System.Windows.Forms.MessageBoxIcon)"
class="OuterNamespace.Portal.Utilities.Forms.MessageBoxEx" method="Show(System.String,System.Windows.Forms.MessageBoxButtons,System.Windows.Forms.MessageBoxIcon)"
class="OuterNamespace.Portal.Components.ExceptionHandler" method="Handle(System.Exception,System.String,OuterNamespace.Portal.Constants.Logging.LogType)"
class="OuterNamespace.Portal.Components.ExceptionHandler" method="HandleException(System.Exception,boolean,OuterNamespace.Interfaces.RuntimeInformation.IRuntimeInformationManager)"
class="OuterNamespace.Exception.Manager.ExceptionManager" method="CallUnhandledExceptionHandler(System.Exception)"
class="OuterNamespace.Exception.Manager.ExceptionManager" method="HandleUnhandledException(System.Exception)"
class="OuterNamespace.Application.ApplicationContext" method="Application_ThreadException(System.Object,System.Threading.ThreadExceptionEventArgs)"
class="System.Windows.Forms.Application+ThreadContext" method="OnThreadException(System.Exception)"
class="System.Windows.Forms.Control" method="WndProcException(System.Exception)"
class="System.Windows.Forms.Control+ControlNativeWindow" method="OnThreadException(System.Exception)"
class="System.Windows.Forms.NativeWindow" method="Callback(System.IntPtr,int,System.IntPtr,System.IntPtr)"
class="System.Windows.Forms.UnsafeNativeMethods" method="SetFocus(System.Runtime.InteropServices.HandleRef)"

------------------------------------------------------------------------
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.FocusActiveControlInternal() Unknown
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.WmSetFocus(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.UserControl.WmSetFocus(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.UserControl.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
[Native to Managed Transition]
[Managed to Native Transition]
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.FocusActiveControlInternal() Unknown
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.WmSetFocus(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Form.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Unknown
Module.dll!MyNamespace.Wrappers.WindowWrapper.WndProc(ref System.Windows.Forms.Message m) Unknown
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) Unknown
[Native to Managed Transition]
[Managed to Native Transition]
Module.dll!MyNamespace.FocusController.FixMouseDoubleClickError.AnonymousMethod__68_0() Unknown
[Native to Managed Transition]
[Managed to Native Transition]
mscorlib.dll!System.Delegate.DynamicInvokeImpl(object[] args) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackDo(System.Windows.Forms.Control.ThreadMethodEntry tme) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(object obj) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallback(System.Windows.Forms.Control.ThreadMethodEntry tme) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbacks() Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.MarshaledInvoke(System.Windows.Forms.Control caller, System.Delegate method, object[] args, bool synchronous) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.Invoke(System.Delegate method, object[] args) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.Invoke(System.Delegate method) Unknown
Module.dll!MyNamespace.FocusController.FixMouseDoubleClickError() Unknown
Module.dll!MyNamespace.FocusController.UpdateAsyncIff.AnonymousMethod__91_0() Unknown
[Native to Managed Transition]
[Managed to Native Transition]
mscorlib.dll!System.Delegate.DynamicInvokeImpl(object[] args) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackDo(System.Windows.Forms.Control.ThreadMethodEntry tme) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(object obj) Unknown
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallback(System.Windows.Forms.Control.ThreadMethodEntry tme) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbacks() Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.MarshaledInvoke(System.Windows.Forms.Control caller, System.Delegate method, object[] args, bool synchronous) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.Invoke(System.Delegate method, object[] args) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Control.Invoke(System.Delegate method) Unknown
Module.dll!MyNamespace.FocusController.FixMouseDoubleClickError() Unknown
Module.dll!MyNamespace.FocusController.HandleCpmModalForegroundWindow(System.IntPtr appForegroundWinHdl) Unknown
Module.dll!MyNamespace.FocusController.HandleForegroundWindowChange(System.IntPtr foregroundDetectedHdl) Unknown
Module.dll!MyNamespace.FocusController.ForegroundWindowChangeDetectorOnForegroundWindowChanged(object sender, MyNamespace.Detectors.ForegroundEventArgs foregroundEventArgs) Unknown
Module.dll!MyNamespace.Detectors.ForegroundWindowChangeDetector.OnForegroundWindowChanged(MyNamespace.Detectors.ForegroundEventArgs e) Unknown
Module.dll!MyNamespace.Detectors.ForegroundWindowChangeDetector.ForegroundCallback(System.IntPtr eventHook, uint eventType, System.IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime) Unknown
[Native to Managed Transition]
[Managed to Native Transition]
System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(System.IntPtr dwComponentID, int reason, int pvLoopData) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason, System.Windows.Forms.ApplicationContext context) Unknown
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) Unknown
Portal.Desktop.exe!OuterNamespace.Portal.Desktop.Program.Main() Unknown

What I have tried:

I am not able to reach to the problem yet so not able to find the workaround or any fix for this.

推荐答案

这是我们得到的最常见的问题之一，而且我也是我们最不能回答的问题，但你最有能力回答自己。



让我解释一下错误的含义：你试过用变量，属性或方法返回值，但它包含null - 这意味着变量中没有类的实例。

它有点像一个口袋：你的口袋里有一个衬衫，你用来握笔。如果你进入口袋并发现那里没有笔，你就不能在一张纸上签名 - 如果你尝试的话，你会得到非常有趣的外观！空口袋给你一个空值（这里没有笔！）所以你不能做任何你检索笔通常做的事情。它为什么空？这就是问题 - 可能是你今天早上离开家时忘了拿起你的笔，或者你昨晚把它拿到昨天的衬衫口袋里时可能会把笔留下来。



我们无法分辨，因为我们不在那里，更重要的是，我们甚至看不到你的衬衫，更不用说口袋里的东西了！



回到计算机，你做了同样的事情，不知何故 - 我们看不到你的代码，更不用说运行它了，找不到包含null的东西。

但是你可以 - 而Visual Studio将在这里帮助你。在调试器中运行您的程序，当它失败时，VS将向您显示它发现问题的行。然后，您可以开始查看它的各个部分，以查看哪个值为null，并开始回顾代码以找出原因。因此，在包含错误行的方法的开头放置一个断点，然后从头再次运行程序。这一次，VS会在错误发生前停止，让你通过查看代码来查看你的价值来检查发生了什么。



但我们做不到那 - 我们没有您的代码，如果我们拥有它，我们不知道如何使用它，我们没有您的数据。所以试试吧 - 看看你能找到多少信息！

This is one of the most common problems we get asked, and it's also the one we are least equipped to answer, but you are most equipped to answer yourself.

Let me just explain what the error means: You have tried to use a variable, property, or a method return value but it contains null - which means that there is no instance of a class in the variable.
It's a bit like a pocket: you have a pocket in your shirt, which you use to hold a pen. If you reach into the pocket and find there isn't a pen there, you can't sign your name on a piece of paper - and you will get very funny looks if you try! The empty pocket is giving you a null value (no pen here!) so you can't do anything that you would normally do once you retrieved your pen. Why is it empty? That's the question - it may be that you forgot to pick up your pen when you left the house this morning, or possibly you left the pen in the pocket of yesterdays shirt when you took it off last night.

We can't tell, because we weren't there, and even more importantly, we can't even see your shirt, much less what is in the pocket!

Back to computers, and you have done the same thing, somehow - and we can't see your code, much less run it and find out what contains null when it shouldn't.
But you can - and Visual Studio will help you here. Run your program in the debugger and when it fails, VS will show you the line it found the problem on. You can then start looking at the various parts of it to see what value is null and start looking back through your code to find out why. So put a breakpoint at the beginning of the method containing the error line, and run your program from the start again. This time, VS will stop before the error, and let you examine what is going on by stepping through the code looking at your values.

But we can't do that - we don't have your code, we don't know how to use it if we did have it, we don't have your data. So try it - and see how much information you can find out!

这篇关于在执行一些与焦点相关的事情时获取nullreferenceexception后，我的应用程序崩溃了的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！